Membranous or diaphragm transmitter for submarine sound-signals.



H. HEGHT.

MEMBRANOUS 0R DIAPHRAGM TRANSMITTER FOR SUBMARINE SOUND SIGNALS.

APPLICATION FILED JULY7, 1913.

1,097,859. Patented May 26,1914.

7 UNITED" STATES PATENT OFFICE.

nnmaicn Know, 0! KIEL, GERMANY.

MEMBRANOUS OR DIAPHRAGM TRANSMITTER FOR SUIBMARINE SOUND-SIGNALS.

To all whom it may concern Be it known that I, HEINRICH HECHT, Dr. PhiL, engineer, a subject ofthe King of Prussia, and resident of 65 Feld street, Kiel, Germany, (whose post-ofiice address is 65 F eld street, Kiel, Germany,) have invented certain new and useful Improvements in Membranous or Diaphragm Transmitters for Submarine Sound-Signals, of Which'the' following is a specification.

The invention relates to a membranous or diaphragm transmitter for submarine sound signals that is to say a device for producing sound vibrations in the side of a hollow body that impinges on the water, for example the outer Sklll of a ship or of a buoy. Attempts have been made to solve this prob lem by directly coupling the ships side or a alternating current.

membrane inserted therein with the armature of an electromagnet, that is excited by In connection herewith the difiiculty has arisen that it has been found to be impossible to transform large outputs of power int-o vibratory energy. The very slight compressibility of water causes even very large acoustic effects to have only very small amplitudes. Thus in order to excite a large mass of water effectively, very great forces are necessary correspondingly to the very small amplitude distances and as the permeability of the electromagnet iron employed only allows of a relatively slight saturation in the case of high frequency of vibration, the available forces can only be increased by simultaneously increasing or enlarging the masses of iron employed in connection wherewith all internal losses increase in equal degree, so that the degree of efiectiveness attained, no matter what dimensions may be adopted, is always far below the most moderate requirements of efficiency and economy. This difficulty could be obviated by causing the energizer, for example an electromagnet to act on the end of a lever and coupling the point of the radiator or of the ships side that is to be energized with a suitably short arm of the lever. As however in view of the small amplitudes, for the production of which it serves, a rigid lever arrangement is difficult or impossible, this form of execution can in general never be perfectly carried out.

The invention consists in introducing between the energizer or the apparatus that transforms the imparted energy into acoustic vibrations, and the radiator or the mem- Specification of Letters Patent.

Application filed J uly 7, 1913. Serial No. 777,753.

Patented May 2c, 1914.

brane that conveys the vibrations to the surroundin water, a system with very pronounced se f-vibration and attunin it so that the frequency of its self-vibration coincides as nearly as possible with that of the impressed vibration. At the same time the form and the dimensions of the transnnsslon system may likewise be such that it contains points, the, amplitudes of which are in the required ratio to the amplitudes pling between the transmission device and the side of the ship.

In the accompanying drawing Figure 1 represents a diagrammatic view of one form of the invention: Fig. 2 is a similar view of a slightly modified form.

In both figuresA is the side of the ship or a side impinging on the water B, and forming the radiator, C is the energizer, which is shown for example as a pair of electromagnets.

D is the transmission device.

In the form shown in Fig. l the transmission device, between the energizer C and the radiator A constitutes a body which has as slight a self-damping action as possible, preferably a tuning fork D is used, and which is so dimensioned that its own periodicity of vibration comes nearest to the required musical pitch and that the requisite ratio is assured between the valves of the amplitudes occurring in the prongs and in the stem. The stem of the tuning fork D thence to the adjoining water B.

The form illustrated in Fig. 2 differs from that in Fig. '1 in that between the stem of the tuning fork and the membrane A a spring H is inserted. Thus between the stem and the membrane there is a further amplitude ratio and the tuning fork therefore does not need to be so dimensioned as to give the full sum of the required transmission.

What I claim and desire to secure by Letters Patent is 1. A transmitter for submarinesound signals comprising means for producing vibrations, a body in ipinginr on the water and adapted to act as a membrane or diaphragm and solid or rigid transmission means introduced between the vibration producing means, and the membrane or diaphragm, and attuned to the periodicity of the vibration producing means.

2. A transn'iitter for submarine sound sig nals comprising a transmission element, a vibration producer arranged to act on the transmission element at points which have great amplitudes of oscillation, and a hollow body impinging on the water and acting as a membrane or diaphragm, and connected with points of the transmission element which have small amplitudes of oscillation.

3. A transmitter for submarine soundsignals comprising means for producing vibrations, a body impinging on the water and adapted to act as a membrane or diaphragm and transmission means introduced between the vibration producing means and the membrane or diaphragm consisting of a vibrating tuning fork or tongue that is as free as possible of damping action, and is coupled with the vibration producing means in proximity to a vibration center, and with the membrane or radiator in proximity to a vibration node.

4-. A transmitter for submarine sound signals comprising an energizer, a radiator, a transmission element and flexible non-damping intermediate parts,vsprings adapted to connect the transmission element with the energizer and the radiator in proximity to vibration centers or nodes.

In testimony whereof I afiix my signature, in presence of two witnesses.

DR. HEINRICH I-IECHT.

WVitnesses C., WILHELM KRUTZFELDE, CLAUmUs HINZ.

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